Method and apparatus for manually selecting a network

ABSTRACT

A method comprising: determining, by a user equipment, that a non-closed access group cell is available to the user equipment in a public land mobile network, wherein the public land mobile network is identified by a public land mobile network identity and the user equipment is only allowed to access the public land mobile network via one or more closed access group cells; displaying the public land mobile network identity to a user; receiving user input selecting the public land mobile network identity; and transmitting a registration request to the public land mobile network identified by the public land mobile network identity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 17/036,729, filed Sep. 29, 2020 and entitled“Method and Apparatus for Manually Selecting a Network,” which claimspriority to, and the benefit of, United Kingdom Patent ApplicationSerial No. 1915748.6, filed Oct. 30, 2019 and entitled “Method andApparatus for Manually Selecting a Network,” the entire disclosures ofeach of which are hereby incorporated herein by reference in theirentireties for all purposes.

TECHNICAL FIELD

The present disclosure relates to an apparatus, a method, and a computerprogram and in particular but not exclusively for an apparatus, methodsand computer programs for manually selecting a network.

BACKGROUND

A communication system can be seen as a facility that enablescommunication sessions between two or more entities such ascommunication devices, base stations/access points and/or other nodes byproviding carriers between the various entities involved in thecommunications path. A communication system can be provided for exampleby means of a communication network and one or more compatiblecommunications devices.

Access to the communication system may be via an appropriatecommunications device or terminal. A communications device is providedwith an appropriate signal receiving and transmitting apparatus forenabling communications, for example enabling access to a communicationnetwork or communications directly with other communications device. Thecommunications device may access a carrier provided by a station oraccess point, and transmit and/or receive communications on the carrier.

The communication system and associated devices typically operate inaccordance with a given standard or specification which sets out whatthe various entities associated with the system are permitted to do andhow that should be achieved.

STATEMENT OF INVENTION

According to an aspect, there is provided a method comprisingdetermining, by a user equipment, that a non-closed access group cell isavailable to the user equipment in a public land mobile network, whereinthe public land mobile network is identified by a public land mobilenetwork identity and the user equipment is only allowed to access thepublic land mobile network via one or more closed access group cells;displaying the public land mobile network identity to a user; receivinguser input selecting the public land mobile network identity; andtransmitting a registration request to the public land mobile networkidentified by the public land mobile network identity.

The public land mobile network identity may be stored in a listcomprising one or more public land mobile network identities, whereinfor each public land mobile network identity there is an associated zeroor more closed access group identities which the user equipment isallowed to use in the public land mobile network identified by thepublic land mobile network identity.

For each public land mobile network identity, there may be an indicationthat the user equipment is only allowed to access a 5G system via closedaccess group cells.

The displayed public land mobile network identity may be associated withan indication that a user equipment is only allowed to access the publicland mobile network identified by the public land mobile networkidentity via one or more closed access group cells.

The method may comprise receiving a registration accept message; anddeleting the indication that the user equipment is only allowed toaccess a 5G system via closed access group cells for the public landmobile network identified by the public land mobile network identity.

The method may comprise receiving a registration reject message; andretaining the indication that the user equipment is only allowed toaccess 5G system via closed access group cells.

Displaying the public land mobile network identity may comprisedisplaying the public land mobile network identity associated with alist of one or more closed access group identities, wherein there existsa closed access group cell available to a user equipment in the publicland mobile network identified by the public land mobile networkidentity, and wherein for each of the closed access group identities, itis indicated whether the user equipment is allowed for the closed accessgroup identity.

The list comprising the one or more closed access group identities mayinclude a closed access group identity field, which is either populatedwith a respective closed access group identity if the entry has a closedaccess group identity, or is populated with an entry indicating a nullclosed access group identity if the entry does not have a closed accessgroup identity.

The method may comprise displaying the public land mobile networkidentity without a list of one or more closed access group identities inaddition to the public land mobile network identity displayed with alist of one or more closed access group identities.

According to an aspect, there is provided an apparatus comprising meansfor determining that a non-closed access group cell is available to theuser equipment in a public land mobile network, wherein the public landmobile network is identified by a public land mobile network identityand the user equipment is only allowed to access the public land mobilenetwork via one or more closed access group cells; displaying the publicland mobile network identity to a user; receiving user input selectingthe public land mobile network identity; and transmitting a registrationrequest to the public land mobile network identified by the public landmobile network identity.

The public land mobile network identity may be stored in a listcomprising one or more public land mobile network identities, whereinfor each public land mobile network identity there is an associated zeroor more closed access group identities which the user equipment isallowed to use in the public land mobile network identified by thepublic land mobile network identity.

For each public land mobile network identity, there may be an indicationthat the user equipment is only allowed to access a 5G system via closedaccess group cells.

The displayed public land mobile network identity may be associated withan indication that a user equipment is only allowed to access the publicland mobile network identified by the public land mobile networkidentity via one or more closed access group cells.

The means may further configured to perform receiving a registrationaccept message; and deleting the indication that the user equipment isonly allowed to access a 5G system via closed access group cells for thepublic land mobile network identified by the public land mobile networkidentity.

The means may further configured to perform receiving a registrationreject message; and retaining the indication that the user equipment isonly allowed to access 5G system via closed access group cells.

Displaying the public land mobile network identity may comprisedisplaying the public land mobile network identity associated with alist of one or more closed access group identities, wherein there existsa closed access group cell available to a user equipment in the publicland mobile network identified by the public land mobile networkidentity, and wherein for each of the closed access group identities, itis indicated whether the user equipment is allowed for the closed accessgroup identity.

The list comprising the one or more closed access group identities mayinclude a closed access group identity field, which is either populatedwith a respective closed access group identity if the entry has a closedaccess group identity, or is populated with an entry indicating a nullclosed access group identity if the entry does not have a closed accessgroup identity.

The means may further configured to perform displaying the public landmobile network identity without a list of one or more closed accessgroup identities in addition to the public land mobile network identitydisplayed with a list of one or more closed access group identities.

According to an aspect, there is provided an apparatus comprising atleast one processor; and at least one memory including computer programcode, the at least one memory and computer program code configured to,with the at least one processor, cause the apparatus to perform:determining that a non-closed access group cell is available to a userequipment in a public land mobile network, wherein the public landmobile network is identified by a public land mobile network identityand the user equipment is only allowed to access the public land mobilenetwork via one or more closed access group cells; displaying the publicland mobile network identity to a user; receiving user input selectingthe public land mobile network identity; and transmitting a registrationrequest to the public land mobile network identified by the public landmobile network identity.

The public land mobile network identity may be stored in a listcomprising one or more public land mobile network identities, whereinfor each public land mobile network identity there is an associated zeroor more closed access group identities which the user equipment isallowed to use in the public land mobile network identified by thepublic land mobile network identity.

For each public land mobile network identity there may be an indicationthat the user equipment is only allowed to access a 5G system via closedaccess group cells.

The displayed public land mobile network identity may be associated withan indication that a user equipment is only allowed to access the publicland mobile network identified by the public land mobile networkidentity via one or more closed access group cells.

The apparatus may be further configured to perform: receiving aregistration accept message; and deleting the indication that the userequipment is only allowed to access a 5G system via closed access groupcells for the public land mobile network identified by the public landmobile network identity.

The apparatus may be further configured to perform: receiving aregistration reject message; and retaining the indication that the userequipment is only allowed to access 5G system via closed access groupcells.

Displaying the public land mobile network identity may comprisedisplaying the public land mobile network identity associated with alist of one or more closed access group identities, wherein there existsa closed access group cell available to a user equipment in the publicland mobile network identified by the public land mobile networkidentity, and wherein for each of the closed access group identities, itis indicated whether the user equipment is allowed for the closed accessgroup identity.

The list comprising the one or more closed access group identities mayinclude a closed access group identity field, which is either populatedwith a respective closed access group identity if the entry has a closedaccess group identity, or is populated with an entry indicating a nullclosed access group identity if the entry does not have a closed accessgroup identity.

The apparatus may be further configured to perform: displaying thepublic land mobile network identity without a list of one or more closedaccess group identities in addition to the public land mobile networkidentity displayed with a list of one or more closed access groupidentities.

According to an aspect, there is provided a non-transitory computerreadable storage medium comprising computer readable instructions, whichwhen run by at least one processor, cause an apparatus to determine thata non-closed access group cell is available to the user equipment in apublic land mobile network, wherein the public land mobile network isidentified by a public land mobile network identity and the userequipment is only allowed to access the public land mobile network viaone or more closed access group cells; display the public land mobilenetwork identity to a user; receive user input selecting the public landmobile network identity; and transmit a registration request to thepublic land mobile network identified by the public land mobile networkidentity.

According to an aspect, there is provided a computer program comprisinginstructions for causing an apparatus to perform at least determiningthat a non-closed access group cell is available to the user equipmentin a public land mobile network, wherein the public land mobile networkis identified by a public land mobile network identity and the userequipment is only allowed to access the public land mobile network viaone or more closed access group cells; displaying the public land mobilenetwork identity to a user; receiving user input selecting the publicland mobile network identity; and transmitting a registration request tothe public land mobile network identified by the public land mobilenetwork identity.

According to an aspect, there is provided an apparatus comprising:determining circuitry for determining that a non-closed access groupcell is available to the user equipment in a public land mobile network,wherein the public land mobile network is identified by a public landmobile network identity and the user equipment is only allowed to accessthe public land mobile network via one or more closed access groupcells; displaying circuitry for displaying the public land mobilenetwork identity to a user; receiving circuitry for receiving user inputselecting the public land mobile network identity; and transmittingcircuitry for transmitting a registration request to the public landmobile network identified by the public land mobile network identity.

According to another aspect, a method can be carried out by means, suchas a computing device or other apparatus, based on computer-executableinstructions, such as instructions stored as program codes. The methodcan include: determining, by a user equipment, that a cell is availableto the user equipment in a public land mobile network, wherein the cellis not a closed access group cell for the public land mobile network;providing, on the user equipment, at least the public land mobilenetwork for user selection; determining, by the user equipment, that apublic land mobile network identity identifying the public land mobilenetwork is associated with an indication that the user equipment is onlyallowed to access a communication system via closed access group cells;indicating, on the user equipment, that the user equipment is onlyallowed to access the public land mobile network via one or more closedaccess group cells; receiving a user selection of the public land mobilenetwork; and, based on the received user selection, transmitting aregistration request to the selected public land mobile network.

In some embodiments, the public land mobile network identity is storedin a list comprising one or more public land mobile network identities,wherein for each public land mobile network identity there is anassociated zero or more closed access group identities which the userequipment is allowed to use in the public land mobile network identifiedby the public land mobile network identity. In some embodiments, foreach public land mobile network identity there is an indication that theuser equipment is only allowed to access a 5G system via closed accessgroup cells. In some embodiments, the method can further include:receiving a registration accept message; and deleting the indicationthat the user equipment is only allowed to access a 5G system via closedaccess group cells for the public land mobile network identified by thepublic land mobile network identity. In some embodiments, the method canfurther include: receiving a registration reject message; and retainingthe indication that the user equipment is only allowed to access 5Gsystem via closed access group cells. In some embodiments, providing thepublic land mobile network comprises displaying the public land mobilenetwork identity associated with a list of one or more closed accessgroup identities, wherein there exists a closed access group cellavailable to a user equipment in the public land mobile networkidentified by the public land mobile network identity, and wherein foreach of the closed access group identities, it is indicated whether theuser equipment is allowed for the closed access group identity.

In some embodiments, the list can include the one or more closed accessgroup identities includes a closed access group identity field, which iseither populated with a respective closed access group identity if theentry has a closed access group identity, or is populated with an entryindicating a null closed access group identity if the entry does nothave a closed access group identity. In some embodiments, the method canfurther include: displaying the public land mobile network identitywithout a list of one or more closed access group identities in additionto the public land mobile network identity displayed with a list of oneor more closed access group identities.

According to another aspect, an apparatus can be provided that includes:at least one processor; and at least one memory including computerprograms code, the at least one memory and computer program code beingconfigured to, with the at least one processor, cause the apparatus atleast to: determine that a cell is available to the apparatus in apublic land mobile network, wherein the cell is not a closed accessgroup cell for the public land mobile network; provide at least thepublic land mobile network for user selection; determine that a publicland mobile network identity identifying the public land mobile networkis associated with an indication that the apparatus is only allowed toaccess a communication system via closed access group cells; indicatethat the apparatus is only allowed to access the public land mobilenetwork via one or more closed access group cells; receive a userselection of the public land mobile network; and, based on the receiveduser selection, transmit a registration request to the selected publicland mobile network.

In some embodiments, the public land mobile network identity is storedin a list comprising one or more public land mobile network identities,wherein for each public land mobile network identity there is anassociated zero or more closed access group identities which theapparatus is allowed to use in the public land mobile network identifiedby the public land mobile network identity. In some embodiments, foreach public land mobile network identity there is an indication that theapparatus is only allowed to access a 5G system via closed access groupcells. In some embodiments, the at least one memory and the computerprogram codes are further configured to, with the at least oneprocessor, cause the apparatus at least to: receive a registrationaccept message; and delete the indication that the apparatus is onlyallowed to access a 5G system via closed access group cells for thepublic land mobile network identified by the public land mobile networkidentity. In some embodiments, the at least one memory and the computerprogram codes are further configured to, with the at least oneprocessor, cause the apparatus at least to: receive a registrationreject message; and retain the indication that the apparatus is onlyallowed to access 5G system via closed access group cells.

In some embodiments, providing the public land mobile network comprisesdisplaying the public land mobile network identity associated with alist of one or more closed access group identities, wherein there existsa closed access group cell available to a apparatus in the public landmobile network identified by the public land mobile network identity,and wherein for each of the closed access group identities, it isindicated whether the apparatus is allowed for the closed access groupidentity. In some embodiments, the list can include the one or moreclosed access group identities includes a closed access group identityfield, which is either populated with a respective closed access groupidentity if the entry has a closed access group identity, or ispopulated with an entry indicating a null closed access group identityif the entry does not have a closed access group identity. In someembodiments, the at least one memory and the computer program codes arefurther configured to, with the at least one processor, cause theapparatus at least to: display the public land mobile network identitywithout a list of one or more closed access group identities in additionto the public land mobile network identity displayed with a list of oneor more closed access group identities.

According to another aspect, a computer program can be provided, such asa computer program embodied on a non-transitory computer-readablemedium. In some embodiments, the computer program can includecomputer-executable codes which, when executed in hardware, cause thehardware to perform at least: determining, by a user equipment, that acell is available to the user equipment in a public land mobile network,wherein the cell is not a closed access group cell for the public landmobile network; providing at least the public land mobile network foruser selection; determining, by the user equipment, that a public landmobile network identity identifying the public land mobile network isassociated with an indication that the user equipment is only allowed toaccess a communication system via closed access group cells; indicating,on the user equipment, that the user equipment is only allowed to accessthe public land mobile network via one or more closed access groupcells; receiving a user selection of the public land mobile network;and, based on the received user selection, transmitting a registrationrequest to the selected public land mobile network.

In some embodiments, the computer-executable code, when executed in thehardware, can further cause the hardware to perform: storing the publicland mobile network identity in a list comprising one or more publicland mobile network identities. In some embodiments, for each publicland mobile network identity there is an associated zero or more closedaccess group identities which the user equipment is allowed to use inthe public land mobile network identified by the public land mobilenetwork identity. In some embodiments, for each public land mobilenetwork identity there is an indication that the user equipment is onlyallowed to access a 5G system via closed access group cells. In someembodiments, the computer-executable code, when executed in thehardware, can further cause the hardware to perform: receiving aregistration accept message; and deleting the indication that the userequipment is only allowed to access a 5G system via closed access groupcells for the public land mobile network identified by the public landmobile network identity.

In the above, many different aspects have been described. It should beappreciated that further aspects may be provided by the combination ofany two or more of the aspects described above.

Various other aspects are also described in the following detaileddescription and in the attached claims.

BRIEF DESCRIPTION OF THE FIGURES

Some example embodiments will now be described in further detail, by wayof example only, with reference to the following examples andaccompanying drawings, in which:

FIG. 1 shows a representation of a network system according to someexample embodiments;

FIG. 2 shows a representation of a control apparatus according to someexample embodiments;

FIG. 3 shows a representation of an apparatus according to some exampleembodiments;

FIG. 4 shows a representation of a registration procedure according tosome example embodiments;

FIG. 5 shows a representation of non-volatile memory media according tosome example embodiments; and

FIG. 6 shows a method according to some example embodiments.

DETAILED DESCRIPTION

In the following certain embodiments are explained with reference tomobile communication devices capable of communication via a wirelesscellular system and mobile communication systems serving such mobilecommunication devices. Before explaining in detail the exemplifyingembodiments, certain general principles of a wireless communicationsystem, access systems thereof, and mobile communication devices arebriefly explained with reference to FIGS. 1, 2 and 3 to assist inunderstanding the technology underlying the described examples.

FIG. 1 shows a schematic representation of a 5G system (5GS). The 5GSmay be comprised by a terminal or user equipment (UE), a 5G radio accessnetwork (5GRAN) or next generation radio access network (NG-RAN), a 5Gcore network (5GC), one or more application function (AF) and one ormore data networks (DN).

The 5G-RAN may comprise one or more gNodeB (GNB) or one or more gNodeB(GNB) distributed unit functions connected to one or more gNodeB (GNB)centralized unit functions.

The 5GC may comprise the following entities: Network Slice SelectionFunction (NSSF); Network Exposure Function; Network Repository Function(NRF); Policy Control Function (PCF); Unified Data Management (UDM);Application Function (AF); Authentication Server Function (AUSF); anAccess and Mobility Management Function (AMF); and Session ManagementFunction (SMF).

FIG. 2 illustrates an example of a control apparatus 200 for controllinga function of the SGRAN or the 5GC as illustrated on FIG. 1 . Thecontrol apparatus may comprise at least one random access memory (RAM)211 a, at least on read only memory (ROM) 211 b, at least one processor212, 213 and an input/output interface 214. The at least one processor212, 213 may be coupled to the RAM 211 a and the ROM 211 b. The at leastone processor 212, 213 may be configured to execute an appropriatesoftware code 215. The software code 215 may for example allow toperform one or more steps to perform one or more of the present aspects.The software code 215 may be stored in the ROM 211 b. The controlapparatus 200 may be interconnected with another control apparatus 200controlling another function of the SGRAN or the 5GC. In someembodiments, each function of the SGRAN or the 5GC comprises a controlapparatus 200. In alternative embodiments, two or more functions of theSGRAN or the 5GC may share a control apparatus.

FIG. 3 illustrates an example of a terminal 300, such as the terminalillustrated on FIG. 1 . The terminal 300 may be provided by any devicecapable of sending and receiving radio signals. Non-limiting examplescomprise a user equipment, a mobile station (MS) or mobile device suchas a mobile phone or what is known as a ‘smart phone’, a computerprovided with a wireless interface card or other wireless interfacefacility (e.g., USB dongle), a personal data assistant (PDA) or a tabletprovided with wireless communication capabilities, a machine-typecommunications (MTC) device, an Internet of things (IoT) typecommunication device or any combinations of these or the like. Theterminal 300 may provide, for example, communication of data forcarrying communications. The communications may be one or more of voice,electronic mail (email), text message, multimedia, data, machine dataand so on.

The terminal 300 may receive signals over an air or radio interface 307via appropriate apparatus for receiving and may transmit signals viaappropriate apparatus for transmitting radio signals. In FIG. 3transceiver apparatus is designated schematically by block 306. Thetransceiver apparatus 306 may be provided for example by means of aradio part and associated antenna arrangement. The antenna arrangementmay be arranged internally or externally to the mobile device.

The terminal 300 may be provided with at least one processor 301, atleast one memory ROM 302 a, at least one RAM 302 b and other possiblecomponents 303 for use in software and hardware aided execution of tasksit is designed to perform, including control of access to andcommunications with access systems and other communication devices. Theat least one processor 301 is coupled to the RAM 311 a and the ROM 311b. The at least one processor 301 may be configured to execute anappropriate software code 308. The software code 308 may for exampleallow to perform one or more of the present aspects. The software code308 may be stored in the ROM 311 b.

The processor, storage and other relevant control apparatus can beprovided on an appropriate circuit board and/or in chipsets. Thisfeature is denoted by reference 304. The device may optionally have auser interface such as key pad 305, touch sensitive screen or pad,combinations thereof or the like. Optionally one or more of a display, aspeaker and a microphone may be provided depending on the type of thedevice.

Certain cells in a wireless communications network may be designated asclosed access group (CAG) cells. A CAG defines a limited group of UEsthat may access a particular CAG cell or group of cells. UEs outside theCAG may not be able to access the cell(s) in the CAG.

In some cases, manual CAG selection may be permitted. In manual CAGselection, a user may be allowed to manually choose a CAG ID that is notin an allowed CAG list. In order to make this functionality available,the UE may display one or more CAG IDs that are not in the allowed CAGlist. The UE may initiate a registration procedure if the user selects anon-allowed CAG ID. If the registration procedure is successful, the UEmay add the selected CAG ID to the allowed CAG list.

In some cases, the UE may only be allowed to access a public land mobilenetwork (PLMN) via certain CAG cells. However, a user may select a PLMNthat is only allowed be accessed via a CAG that is not in the allowedCAG list. As such, the user may have to be able to select a PLMN withoutselecting a CAG, even if the UE is only allowed to access the PLMN viaCAG cells.

In some example embodiments, there is provided a method as shown in FIG.6 .

At step 600, the method comprises determining, by a user equipment, thata non-closed access group cell is available to the user equipment in apublic land mobile network. The public land mobile network is identifiedby a public land mobile network identity and the user equipment is onlyallowed to access the public land mobile network via one or more closedaccess group cells.

At step 602, the method comprises displaying the public land mobilenetwork identity to a user.

At step 604, the method comprises receiving user input selecting thepublic land mobile network identity.

At step 606, the method comprises transmitting a registration request tothe public land mobile network identified by the public land mobilenetwork identity.

An example of a registration procedure according to some exampleembodiments is shown in FIG. 4 .

As shown in FIG. 4 , the user equipment transmits, to an accessmanagement function (AMF), a message comprising a registration request.

When the registration procedure is successful, the AMF transmits to theuser equipment a registration accept message. Or if the registrationprocedure is not successful, for example if the AMF needs to reject theregistration request from the UE, the AMF sends a registration rejectmessage.

In some example embodiments, the displayed information indicating one ormore public land mobile networks may indicate which public land mobilenetworks are available using all supported radio access technologies.PLMNs meeting the criteria above may presented in the following order:

i) if one or more equivalent home public land mobile networks (EHPLMNs)are available, then based on an optional data field on a universalmobile telecommunications system subscriber identification module (USIM)either only the highest priority available EHPLMN is to be presented tothe user, or all available EHPLMNs are presented to the user in priorityorder. Alternatively, if an EHPLMN list is not present or is empty, orif the data field is not present on the USIM, the home public landmobile network (HPLMN) is presented instead of the EHPLMN.

ii) PLMN/radio access technology combinations contained in the USIM, inpriority order. The PLMN/radio access technologies may be stored in a“User Controlled PLMN Selector with Access Technology” data file in theUSIM;

iii) PLMN/radio access technology combinations contained in the USIM, inpriority order. The PLMN/radio access technology combinations may bestored in an “Operator Controlled PLMN Selector with Access Technology”data file in the USIM. Additionally or alternatively, the PLMN/radioaccess technology combinations may be stored in a mobility engine (ME);

iv) other PLMN/access technology combinations with received a highestquality signal. If more than one PLMN/radio access technology have thesame highest signal quality, the more than one PLMN/radio accesstechnologies with the highest signal quality may be displayed in arandom order; and

v) other PLMN/radio access technology combinations in order ofdecreasing signal quality.

In some example embodiments, if the UE supports the CAG feature, and theallowed CAG list comprises at least one entry, then for each PLMN/radioaccess technology combination of NG-RAN access technology, the UE maydisplay the PLMN/radio access technology combination and a list of oneor more CAG identifiers (IDs), such that for each CAG-ID there is anavailable CAG cell which broadcasts the CAG-ID for the PLMN. Inaddition, if there exists an entry with the PLMN ID of the PLMN in a“CAG information list” and the CAG-ID is included in the allowed CAGlist, the UE may display an indication that the CAG-ID is allowed.Additionally or alternatively, the UE may display whether the CAG-ID isallowed whenever a CAG-ID is displayed.

Alternatively, in some example embodiments the UE may display thePLMN/radio access technology combination without a list of CAG-IDs, ifthere is an available cell which is nota CAG cell for the PLMN. Inaddition, if there exists an entry with the PLMN ID of the PLMN in the“CAG information list” including an indication that the UE is onlyallowed to access 5GS via CAG cells, the UE may present to the user anindication that the UE is only allowed to access 5GS (or the PLMN) viaCAG cells. Additionally or alternatively, the UE may display whether theUE is only allowed to access the PLMN via CAG cells whenever aPLMN/radio access technology combination is displayed without a list ofCAG-IDs.

In some example embodiments, if there exists both an available CAG celland an available non-CAG NG-RAN cell for the PLMN, the PLMN/radio accesstechnology combination may be displayed twice: firstly a list ofPLMN/radio access technology combinations with CAG-IDs and the secondlya list of PLMN/radio access technology combinations without CAG-IDs.

Alternatively, in some example embodiments the UE may display a list ofPLMN/access technology combinations once. The list may include a CAG-IDfield, which is either populated with the CAG ID if an entry has a CAGID, or is populated with an entry indicating a null CAG-ID if the entrydoes not have a CAG ID.

In some example embodiments, how the UE displays the PLMN/radio accesstechnology combination and a list of CAG-IDs, such that there existsboth an available CAG cell and an available non-CAG NG-RAN cell for thePLMN, may be UE implementation specific.

In some example embodiments, the UE may initiate the registrationprocedure by sending a REGISTRATION REQUEST message to the AMF wheneither:

(a) the UE has selected a CAG-ID which is not included in the allowedCAG list for the selected PLMN; or

(b) a CAG-ID in a PLMN for which the entry in the “CAG information list”does not exist; or

(c) the UE has selected, without selecting a CAG-ID, a PLMN for whichthe entry in the “CAG information list” includes an indication that theUE is only allowed to access 5GS via CAG cells.

If the UE has initiated the registration procedure due to manual CAGselection and receives a REGISTRATION ACCEPT message and the UE hasinitiated the registration procedure in a CAG cell, then the UE may addthe selected CAG-ID in the allowed CAG list for the current PLMN (if notalready included).

Alternatively, if the UE has initiated the registration procedure due tomanual CAG selection and receives a REGISTRATION ACCEPT message and theUE has initiated the registration procedure in a non-CAG cell, then theUE may delete an indication that the UE is only allowed to access 5GSvia CAG cells” from the entry of the “CAG information list” for thecurrent PLMN (if any).

In some example embodiments, the AMF may reject a registration requestfrom the UE if the UE does not pass CAG access control. In this case,the AMF can send a REGISTRATION REJECT message and “CAG informationlist” or part of the “CAG information list”. For example, if the UEaccesses a PLMN with selecting a CAG-ID which the UE is not allowed touse in the PLMN, the network can send the allowed CAG list for the PLMNtogether with the REGISTRATION REJECT message.

FIG. 5 shows a schematic representation of non-volatile memory media 500a (e.g. computer disc (CD) or digital versatile disc (DVD)) and 500 b(e.g. universal serial bus (USB) memory stick) storing instructionsand/or parameters 502 which when executed by a processor allow theprocessor to perform one or more of the steps of the methods describedpreviously.

It is to be noted that embodiments of the present invention may beimplemented as circuitry, in software, hardware, application logic or acombination of software, hardware and application logic. In an exampleembodiment, the application logic, software or an instruction set ismaintained on any one of various conventional computer-readable media.In the context of this document, a “computer-readable medium” may be anymedia or means that can contain, store, communicate, propagate ortransport the instructions for use by or in connection with aninstruction execution system, apparatus, or device, such as a computeror smart phone, or user equipment.

As used in this application, the term “circuitry” refers to all of thefollowing: (a) hardware-only circuit implementations (such asimplementations in only analog and/or digital circuitry) and (b) tocombinations of circuits and software (and/or firmware), such as (asapplicable): (i) to a combination of processor(s) or (ii) to portions ofprocessor(s)/software (including digital signal processor(s)), software,and memory(ies) that work together to cause an apparatus, such as amobile phone or server, to perform various functions) and (c) tocircuits, such as a microprocessor(s) or a portion of amicroprocessor(s), that require software or firmware for operation, evenif the software or firmware is not physically present. This definitionof ‘circuitry’ applies to all uses of this term in this application,including in any claims. As a further example, as used in thisapplication, the term “circuitry” would also cover an implementation ofmerely a processor (or multiple processors) or portion of a processorand its (or their) accompanying software and/or firmware. The term“circuitry” would also cover, for example and if applicable to theparticular claim element, a baseband integrated circuit or applicationsprocessor integrated circuit for a mobile phone or a similar integratedcircuit in server, a cellular network device, or other network device.

The described features, advantages, and characteristics of the inventioncan be combined in any suitable manner in one or more embodiments. Oneskilled in the relevant art will recognize that the invention can bepracticed without one or more of the specific features or advantages ofa particular embodiment. In other instances, additional features andadvantages can be recognized in certain embodiments that may not bepresent in all embodiments of the invention. One having ordinary skillin the art will readily understand that the invention as discussed abovemay be practiced with steps in a different order, and/or with hardwareelements in configurations which are different than those which aredisclosed. Therefore, although the invention has been described basedupon these preferred embodiments, it would be apparent to those of skillin the art that certain modifications, variations, and alternativeconstructions would be apparent, while remaining within the spirit andscope of the invention.

What is claimed is:
 1. A method, comprising: determining, by a userequipment, that a cell is available to the user equipment in a publicland mobile network, wherein the cell is not a closed access group cellfor the public land mobile network; providing, on the user equipment, atleast the public land mobile network for user selection; determining, bythe user equipment, that a public land mobile network identityidentifying the public land mobile network is associated with anindication that the user equipment is only allowed to access acommunication system via closed access group cells; indicating, on theuser equipment, that the user equipment is only allowed to access thepublic land mobile network via one or more closed access group cells;receiving a user selection of the public land mobile network; and basedon the received user selection, transmitting a registration request tothe selected public land mobile network .
 2. The method of claim 1,wherein the public land mobile network identity is stored in a listcomprising one or more public land mobile network identities, whereinfor each public land mobile network identity there is an associated zeroor more closed access group identities which the user equipment isallowed to use in the public land mobile network identified by thepublic land mobile network identity.
 3. The method of claim 2, whereinfor each public land mobile network identity there is an indication thatthe user equipment is only allowed to access a 5G system via closedaccess group cells.
 4. The method of claim 1, comprising: receiving aregistration accept message; and deleting the indication that the userequipment is only allowed to access a 5G system via closed access groupcells for the public land mobile network identified by the public landmobile network identity.
 5. The method of claim 1, comprising: receivinga registration reject message; and retaining the indication that theuser equipment is only allowed to access 5G system via closed accessgroup cells.
 6. The method of claim 1, wherein providing the public landmobile network comprises displaying the public land mobile networkidentity associated with a list of one or more closed access groupidentities, wherein there exists a closed access group cell available toa user equipment in the public land mobile network identified by thepublic land mobile network identity, and wherein for each of the closedaccess group identities, it is indicated whether the user equipment isallowed for the closed access group identity.
 7. The method of claim 6,wherein the list comprising the one or more closed access groupidentities includes a closed access group identity field, which iseither populated with a respective closed access group identity if theentry has a closed access group identity, or is populated with an entryindicating a null closed access group identity if the entry does nothave a closed access group identity.
 8. The method of claim 8,comprising: displaying the public land mobile network identity without alist of one or more closed access group identities in addition to thepublic land mobile network identity displayed with a list of one or moreclosed access group identities.
 9. An apparatus, comprising: at leastone processor; and at least one memory including computer programs code,the at least one memory and computer program code being configured to,with the at least one processor, cause the apparatus at least to:determine that a cell is available to the apparatus in a public landmobile network, wherein the cell is not a closed access group cell forthe public land mobile network; provide at least the public land mobilenetwork for user selection; determine that a public land mobile networkidentity identifying the public land mobile network is associated withan indication that the apparatus is only allowed to access acommunication system via closed access group cells; indicate that theapparatus is only allowed to access the public land mobile network viaone or more closed access group cells; receive a user selection of thepublic land mobile network; and based on the received user selection,transmit a registration request to the selected public land mobilenetwork.
 10. The apparatus of claim 9, wherein the public land mobilenetwork identity is stored in a list comprising one or more public landmobile network identities, wherein for each public land mobile networkidentity there is an associated zero or more closed access groupidentities which the apparatus is allowed to use in the public landmobile network identified by the public land mobile network identity.11. The apparatus of claim 10, wherein for each public land mobilenetwork identity there is an indication that the apparatus is onlyallowed to access a 5G system via closed access group cells.
 12. Theapparatus of claim 9, wherein the at least one memory and the computerprogram codes are further configured to, with the at least oneprocessor, cause the apparatus at least to: receive a registrationaccept message; and delete the indication that the apparatus is onlyallowed to access a 5G system via closed access group cells for thepublic land mobile network identified by the public land mobile networkidentity.
 13. The apparatus of claim 9, wherein the at least one memoryand the computer program codes are further configured to, with the atleast one processor, cause the apparatus at least to: receive aregistration reject message; and retain the indication that theapparatus is only allowed to access 5G system via closed access groupcells.
 14. The apparatus of claim 9, wherein providing the public landmobile network comprises displaying the public land mobile networkidentity associated with a list of one or more closed access groupidentities, wherein there exists a closed access group cell available toa apparatus in the public land mobile network identified by the publicland mobile network identity, and wherein for each of the closed accessgroup identities, it is indicated whether the apparatus is allowed forthe closed access group identity.
 15. The apparatus of claim 14, whereinthe list comprising the one or more closed access group identitiesincludes a closed access group identity field, which is either populatedwith a respective closed access group identity if the entry has a closedaccess group identity, or is populated with an entry indicating a nullclosed access group identity if the entry does not have a closed accessgroup identity.
 16. The apparatus of claim 15, wherein the at least onememory and the computer program codes are further configured to, withthe at least one processor, cause the apparatus at least to: display thepublic land mobile network identity without a list of one or more closedaccess group identities in addition to the public land mobile networkidentity displayed with a list of one or more closed access groupidentities.
 17. A computer program embodied on a non-transitorycomputer-readable medium, the computer program comprisingcomputer-executable codes which, when executed in hardware, cause thehardware to perform at least: determining, by a user equipment, that acell is available to the user equipment in a public land mobile network,wherein the cell is not a closed access group cell for the public landmobile network; providing at least the public land mobile network foruser selection; determining, by the user equipment, that a public landmobile network identity identifying the public land mobile network isassociated with an indication that the user equipment is only allowed toaccess a communication system via closed access group cells; indicating,on the user equipment, that the user equipment is only allowed to accessthe public land mobile network via one or more closed access groupcells; receiving a user selection of the public land mobile network; andbased on the received user selection, transmitting a registrationrequest to the selected public land mobile network.
 18. The computerprogram of claim 17, wherein the computer-executable code, when executedin the hardware, further cause the hardware to perform: storing thepublic land mobile network identity in a list comprising one or morepublic land mobile network identities, wherein for each public landmobile network identity there is an associated zero or more closedaccess group identities which the user equipment is allowed to use inthe public land mobile network identified by the public land mobilenetwork identity.
 19. The computer program of claim 18, wherein for eachpublic land mobile network identity there is an indication that the userequipment is only allowed to access a 5G system via closed access groupcells.
 20. The computer program of claim 17, wherein thecomputer-executable code, when executed in the hardware, further causethe hardware to perform: receiving a registration accept message; anddeleting the indication that the user equipment is only allowed toaccess a 5G system via closed access group cells for the public landmobile network identified by the public land mobile network identity.